干旱区生态环境知识资源中心(Arid): Long term variation of evapotranspiration and water balance based on upscaling eddy covariance observations over the temperate semi-arid grassland of China

Arid

DOI	10.1016/j.agrformet.2021.108566
	Long term variation of evapotranspiration and water balance based on upscaling eddy covariance observations over the temperate semi-arid grassland of China
	Pang, Xinxin; Lei, Huimin; Cong, Zhentao; Yang, Hanbo; Duan, Limin; Yang, Dawen
通讯作者	Lei, HM (corresponding author), Tsinghua Univ, Dept Hydraul Engn, Beijing, Peoples R China.
来源期刊	AGRICULTURAL AND FOREST METEOROLOGY
ISSN	0168-1923
EISSN	1873-2240
出版年	2021
卷号	308
英文摘要	As an important part of global semi-arid grassland, adequately understanding the spatio-temporal variability of evapotranspiration (ET) and water balance (WB, defined as precipitation-ET) over the temperate semi-arid grassland of China (TSGC) could advance our understanding of climate, hydrological and ecological processes over global semi-arid areas. Based on the largest number of in-situ ET measurements (13 flux towers) within the TSGC, we applied the support vector regression (SVR) method to develop a high-quality ET dataset for the TSGC from 1982 to 2015. The model performed well in validation against flux tower-measured data and comparison with water-balance derived ET. The annual ET ranged from 226 to 294 mm yr(-1) with an average of 250 mm yr(-1) and an insignificant trend during 1982-2015. Nevertheless, ET increased significantly during 1982-1998, and turn to decrease during 1999-2011. Regional WB, which approximately represents water availability, fluctuated without a significant trend for entire period. But the annual mean WB at 1999-2011 decreased by 26.1% compared with that before 1998. On average, ET was dominated by climatic factors, especially precipitation, rather than human activities. The reversal of ET trend after 1998 was predominantly explained by the slow increase of precipitation, the stalled increase of temperature, and the significantly decreasing radiation. The revegetation programs exacerbated the evaporative water consumption significantly in some areas after 1998, such as Yellow River Basin. The variation of WB was mainly driven by precipitation, whether in time or space. In addition, the spatio-temporal difference between our SVR ET dataset with four widely used global ET datasets (i.e., GLEAM, FLUXCOM, MODIS, and BESS) suggested that none of these four products can capture both the magnitude and variability of ET well in the TSGC, and local observations are of great importance.
英文关键词	Evapotranspiration Water balance Spatio-temporal variation Support vector regression Eddy covariance observations The temperate semi-arid grassland of China
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000692679900028
WOS关键词	CONTERMINOUS UNITED-STATES ; TERRESTRIAL EVAPOTRANSPIRATION ; SPATIOTEMPORAL PATTERN ; COMBINING MODIS ; CLIMATE-CHANGE ; LOESS PLATEAU ; FLUX TOWERS ; LAND-COVER ; PRODUCTS ; SATELLITE
WOS类目	Agronomy ; Forestry ; Meteorology & Atmospheric Sciences
WOS研究方向	Agriculture ; Forestry ; Meteorology & Atmospheric Sciences
来源机构	清华大学
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/362354
作者单位	[Pang, Xinxin; Lei, Huimin; Cong, Zhentao; Yang, Hanbo; Yang, Dawen] Tsinghua Univ, Dept Hydraul Engn, State Key Lab Hydrosci & Engn, Beijing 100084, Peoples R China; [Pang, Xinxin; Lei, Huimin; Yang, Hanbo; Yang, Dawen] Cooperat Innovat Ctr Water Safety & Hydro Sci, Nanjing 210098, Jiangsu, Peoples R China; [Duan, Limin] Inner Mongolia Agr Univ, Coll Water Conservancy & Civil Engn, Hohhot 010018, Peoples R China
推荐引用方式 GB/T 7714	Pang, Xinxin,Lei, Huimin,Cong, Zhentao,et al. Long term variation of evapotranspiration and water balance based on upscaling eddy covariance observations over the temperate semi-arid grassland of China[J]. 清华大学,2021,308.
APA	Pang, Xinxin,Lei, Huimin,Cong, Zhentao,Yang, Hanbo,Duan, Limin,&Yang, Dawen.(2021).Long term variation of evapotranspiration and water balance based on upscaling eddy covariance observations over the temperate semi-arid grassland of China.AGRICULTURAL AND FOREST METEOROLOGY,308.
MLA	Pang, Xinxin,et al."Long term variation of evapotranspiration and water balance based on upscaling eddy covariance observations over the temperate semi-arid grassland of China".AGRICULTURAL AND FOREST METEOROLOGY 308(2021).